Modular limb segment connector

ABSTRACT

A joint assembly for releasably securing a first and a second segment of an associated modular limb is provided. The joint assembly includes a male connector including a base and a load bearing blade secured to the base of the male connector protruding therefrom. The male connector is adapted to be secured to one of the first and second segments of the associated modular limb. A female connector is provided and includes a base and a load bearing socket secured to the base of the female connector. The socket is configured to selectively receive the blade of the male connector. The female connector is adapted to be secured to the other of the first and second segments of the associated modular limb. A locking member selectively retains the blade of the male connector in the socket of the female connector. The male connector, the female connector, and the locking member cooperate to form a resilient and selectively releasable modular limb joint.

A claim for domestic priority is made herein under 35 U.S.C. §119(e) toU.S. Provisional App. Ser. No. 61/267,629 filed on Dec. 8, 2009, theentire disclosure of which is incorporated herein by reference.

BACKGROUND

The present disclosure relates to man-made or artificial limbs forprosthetic or orthotic devices, as well as for robots. Moreparticularly, it relates to a modular limb segment connector, such as anarm segment connector, which can be used in prosthetics, as well as forrobotics applications when an artificial limb is required.

In the field of prosthetics, there remains a limited ability to controlprosthetic and/or orthotic joints in a suitable manner for practicalclinical application. While great strides have been made in prostheticlegs, the development of prosthetic arms has not been as advanced.Typically, limbs such as arms, whether for prosthetics or robotics, areassembled with custom bolted and screwed mechanical connections that aredifferent for each joint. These mechanical connections may or may notinclude the electrical interconnections between adjacent arm components.Typical solutions can include complex wiring harnesses that requirebulky electrical connectors or solder connections. Such solutions aredisadvantageous because they only work for a specific joint. In otherwords, they are not usable for joints between multiple arm modules.

Although prosthetic technology has advanced in recent years, the priorart still has failed to bridge the gap between manmade prosthetics anduser demands and needs. Therefore, an extensive opportunity for designadvancements and innovation remains where the prior art fails or isdeficient. Most myoelectric prosthetic arms move in three ways. Theybend at the elbow, rotate at the wrist and a rudimentary hand clampsshut. A need exists to replicate the great many varieties of movementsthat a human arm is capable of making. It is believed that a human armhas 27 degrees of freedom, including individual finger bending, and theuse of an opposable thumb. Robotic arms used as prostheses are not fullyarticulated to give the user the same degrees of freedom as a naturalarm, not to mention the speed and torque of a human arm. Moreover, thehuman arm can sense pressure, which conventional man-made arms cannotdo. It would be advantageous if the prosthetic or robotic arm wassensitive enough to pick up a piece of paper, a wine glass or even agrape without mishap.

While many advances are taking place to allow for better prosthetics andorthotics, as well as more functional robotic limbs, there remains aneed to develop better connections for the various segments of a limb sothat the segments can be more readily attached and detached in a simplemanner, without external wiring, and in a manner that provides a weathertight seal. It would also be advantageous to provide sensors for torquebeing transmitted between adjacent components of a limb.

BRIEF DISCLOSURE OF THE DEVELOPMENT

According to one aspect of the present disclosure, a joint assembly forreleasably securing a first and a second segment of an associatedmodular limb is provided. The joint assembly includes a male connectorincluding a base and a load bearing blade secured to the base of themale connector protruding therefrom. The male connector is adapted to besecured to one of the first and second segments of the associatedmodular limb. A female connector is provided and includes a base and aload bearing socket secured to the base of the female connector. Thesocket is configured to selectively receive the blade of the maleconnector. The female connector is adapted to be secured to the other ofthe first and second segments of the associated modular limb. A lockingmember selectively retains the blade of the male connector in the socketof the female connector. The male connector, the female connector, andthe locking member cooperate to form a resilient and selectivelyreleasable modular limb joint.

According to another aspect of the present disclosure, another jointassembly for releasably securing a first and a second segment of anassociated modular limb is provided. The joint assembly includes a maleconnector including a base, a load bearing hub secured to the base ofthe male connector, and at least one first electrical contact secured tothe load bearing hub. The base of the male connector is adapted to besecured to one of the first and second segments of the associatedmodular limb. A female connector is provided including a base, a loadbearing socket secured to the base of the female connector, and at leastone second electrical contact secured to the load bearing socket. Thesocket is configured to selectively receive the hub of the maleconnector and the base of the female connector is adapted to be securedto the other of the first and second segments of the associated modularlimb. The at least one first electrical contact is aligned with the atleast one second electrical contact when the hub is received in thesocket for establishing electrical communication between the first andsecond segments of the associated modular limb. The male connector andthe female connector cooperate to form a resilient yet releasablemodular limb joint.

According to yet another aspect of the present disclosure, a torquesensing quick-release joint assembly is provided for selectivelysecuring a first segment of an associated artificial limb to a secondsegment thereof and sensing a torque transmitted therebetween. The jointassembly includes a male connector including a base and a load bearingprojection secured to the base of the male connector. The base of themale connector is adapted to be secured to one of the first and secondsegments of the associated artificial limb. A female connector includesa base and a load bearing socket secured to the base of the femaleconnector. The socket is configured to selectively receive theprojection of the male connector. The base of the female connector isadapted to be secured to the other of the first and second segments ofthe associated artificial limb. A load sensor is secured to one of themale and female connectors for measuring a torsional load transmittedthrough the joint assembly. The male connector and the female connectorcooperate to form a resilient yet releasable artificial limb joint.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B show a fully assembled and mated connector according toa first embodiment of the present disclosure.

FIG. 2 shows a partially disassembled connector of FIG. 1A with alocking clip removed and male and female connector sides partiallyremoved from each other.

FIGS. 3A and 3B show the connector of FIG. 2 in a fully disassembledcondition.

FIGS. 4A and 4B show exploded views of the female side of the connectorof FIG. 2.

FIGS. 5A and 5B show exploded views of the male side of the connector ofFIG. 2.

FIGS. 6A and 6B show exploded views of the blade and electrical contactassembly of the male side of the connector of FIG. 2.

FIG. 7 shows an exploded view of the locking clip assembly of theconnector of FIG. 2.

FIG. 8 shows a fully engaged and clamped connector according to a secondembodiment of the present disclosure.

FIG. 9 shows the connector of FIG. 8 with a locking lever open.

FIG. 10 shows the connector of FIG. 8 with the locking lever open andmale and female sides disengaged.

FIGS. 11 and 12 show exploded views of a connector assembly of FIG. 8.

FIG. 13 shows an exploded view of the male side of the connector of FIG.8.

FIGS. 14 and 15 show exploded views of the female side of the connectorof FIG. 8.

FIG. 16 shows an exploded view of a locking lever assembly of theconnector of FIG. 8.

FIGS. 17-20 show the steps involved in securing a first limb element toa second limb element when employing the male side assembly and femaleside assembly illustrated in FIGS. 1A-7.

DETAILED DESCRIPTION OF THE FIRST EMBODIMENT

One embodiment of the connector or modular joint assembly 1 for anartificial limb is shown in FIGS. 1A through 7. As is shown in thedrawings and particularly in FIG. 2, the joint assembly includes a maleside connector 3 which slides into a female side connector 12. A lockingmember or clip assembly 11 secures the two sides of the connector. Themale connector, female connector, and locking member cooperate to formthe resilient yet selectively releasable modular limb joint 1.

When fully assembled, in the embodiment shown in FIGS. 1A and 1B, thejoint assembly 1 forms a compact assembly that provides robustmechanical attachment, multiple weather-sealed electrical connections,and integral torque sensing. As is shown in particular in FIGS. 3A and3B, the mechanical attachment between the female side connector 12 andmale side connector 3 is achieved when blade 10 or other load bearingprojection of the male side connector assembly slides into a socket 29or other receiver in the female connector 12. In particular, FIG. 3Bshows that a U-shaped socket 29 is defined in the female side assembly12 for this purpose. In the instant embodiment, blade 10 is receivedinto or under the lip 17 in the socket 29. Electrical contact orcommunication through the joint can be achieved via one or more flatcontacts 2, 2A, 2B, 2C, 4, and 9 in the male connector 3 which engagesuitable elements in the female connector 12. By way of example only,electrical communication is established when the plurality of springpins 18 (see FIG. 4B) in the female side connector 12 are seated againstthe contacts in the male connector as would typically occur upon fullinsertion of the blade 10 into the socket 29. Also, a pocket 5 (FIG. 3B)is formed above the socket 29 for receiving the locking clip assembly 11once the male and female connectors are fully joined or engaged.

A unique feature of the instant disclosure is the ability of the modularlimb joint assembly to sense torque, load, and/or pressure, etc. aboutthe cylindrical axis of the connector assembly (or the axis of rotationof the joint). This can be measured by means of strain gages 13A and 13Band a strain gage signal conditioning circuit board 8 (FIGS. 3B, 5A and5B) mounted to the back of the male blade 10. One or more electricalconnectors 43 can be used for maintaining electrical communication tothe conditioning circuit board 8, strain gages 13A, 13B, and/or otherelectronics through the various components of the limb, joint assembly,or individual male/female connectors. It should be noted that the straingages 13A, 13B could include a full, half, or quarter strain gagebridge.

While the use of strain gages is illustrated in the instant disclosure,other torque or load sensing devices can be used such as load cells,piezoelectric sensors, or pressure/strain sensing semiconductors, etc.In addition, position sensors could be used to measure the relativerotational displacement between the male/female connectors of the jointwhich can then be used to calculate the associated torque and/or loadvalues.

Such torque or load sensing capability is advantageous for a number ofreasons. For one, it allows for a modular limb controller to properlylimit the stresses that the joint and limb are subject to therebypreventing damage to the joint and/or limb. In addition, such loadand/or torque information can be used by the controller to moreaccurately control limb motion, position, and/or to provide bio-feedbackcontrol, sensation, etc. for prosthetic limb users. An additionaladvantage is that torque or load sensing allows precise control offorces being exerted by the prosthetic limb on external objects (orpeople), thus preventing damage or injury to those objects or people.Furthermore, precise force control further enhances the stability of thesystem and/or limb as well as the stability of the objects beingmanipulated. Moreover, torque and/or load sensing is also advantageousfor controlling the impedance of each joint for the same reasons thatforce or torque control is.

As is shown in the exploded views in FIGS. 4A and 4B, the female sideconnector/assembly 12 may include a spring pin mounting circuit board 24having electrical contacts 6, 6A, 6B, 6C, 6D, and 6E (FIG. 3A),electrical spring pins 18 in spring pin blocks 25 (which are inelectrical communication with contacts 6-6E), a socket or receiver plate34, a connection backing 35, an o-ring 26, an electrical contactinsulating member 28, and a connection plain bearing 20. As illustratedin FIGS. 4A and 4B, the spring pin circuit board 24 supports the springpin blocks 25 which are both seated or received in a recess 27 of theconnection backing 35. The insulating member 28 and the o-ring 26 aregenerally secured to either the spring pin circuit board 24, the springblocks 25, and/or the connection backing 35. A plurality of screws 32,33 can then be used to fasten together the socket or receiver plate 34and the connection backing 35 (via holes 30, 22) to a respective modularlimb segment. Once assembled, the socket or female receiver 29 is formedbetween the lip 17 of the socket plate 34 and the connection backing 35.Power and ground contacts 4 and 9 of the male joint connector 12 caneach be contacted by multiple spring pins 18 to allow high electricalcurrents to flow across the joint.

The male side connector/assembly 3, shown in exploded views in FIGS. 5Aand 5B, can include a torsion member 37, a backing sheet 38, a shim 40,a connector side plain bearing 41, a drive support 39, a male jointconnector subassembly 42, strain gages 13A and 13B for measurement oftorque in the connector/joint, a connection printed circuit board 8, andinternal wiring 15. A plurality of countersunk clearance holes 21 may beused to allow the male side assembly to be bolted to an artificial armassembly or respective segment of the modular limb (see FIGS. 17-20).

FIGS. 6A and 6B show exploded views of the male joint connectorsubassembly 42. In particular, the conductive power and ground contacts4 and 9, the conductive communications bus contacts 2, 2A, 2B, and 2C,an electrically insulating connection plug 44, and the blade 10 (whichmay be made from hardened steel) are shown. In addition, knurling 45 canbe formed on the housing 49 of the male joint connector subassembly 42which increases the contact area with the toothed outer periphery of thepolymer material of the torsion member 37. This helps improve themechanical bond and prevent or retard the torsion member from slipping.It should be noted the torsion member can be a torsional springmanufactured from any material (plastic, rubber, metal, etc.) having theappropriate spring characteristics for the particular parameters(maximum load, stiffness, etc.) which the joint is designed toaccommodate.

The locking clip assembly 11, shown in an exploded view in FIG. 7,includes a plain bearing 23, a lock or clip 46, and socket cap screws 19and 19A. The plain bearing 23 (which can be made from a polymer basedmaterial) in this embodiment fits into recess 47 in lock 46 and thescrews 19 and 19A fit into the counterbored clearance holes 48 and 48A.

Operation of the First Embodiment

In operation, the male side connector/assembly 3 and female sideconnector/assembly 12 can be attached to separate artificial armsections (e.g., see modules A and B as shown in FIGS. 17-20). These canbe a humeral rotator and an elbow, as illustrated in FIGS. 17-20.However, they can, instead, be other limb segments of an arm or a leg ora robot. As is shown in FIG. 2, the joint connection process begins byfirst sliding blade 10 of male side connector 3 into the socket/receiver29 of female side connector 12. The joint connection is fullyestablished when blade 10 is fully engaged in a sliding interference fitwith edge or lip 17 in receiver/socket 29. These steps are shown inFIGS. 17 and 19. When full engagement is achieved then power and groundcontacts 4 and 9 are in intimate contact with the plurality ofconductive spring pins 18, and communications contacts 2, 2A, 2B, and 2Care each in intimate contact with its respective spring pin 18.

To ensure that the male side connector 3 and female side connector 12 donot become disengaged during service or operation, the locking clipassembly 11 is inserted into receiver 29 after blade 10 is fully engagedwith edge/lip 17. In the embodiment shown, the screws 19 and 19A (seeFIG. 7) are driven into threaded holes 31 (see FIGS. 4A-4B) andtightened. Of course, other ways of securing the locking clip in place,in a manner that the clip can be detached as needed when disassemblingthe joint, are also contemplated. The modular limb joint assembly 1 isthus configured as shown in FIGS. 1A and 1B. Similarly, FIG. 20 showsthe two arm section modules in a connected fashion. In the embodimentshown, the first arm section can be the humeral rotator A and the secondarm section can be an elbow B. However, other embodiments are alsocontemplated. In other words, the two limb sections which are joined canbe, for example, a wrist connection to a forearm or an upper armconnection to a shoulder.

When the male and female connectors are fully engaged, blade 10transfers rotational and linear mechanical loads from the male connector3 to the socket/receiver 29 in the female connector 12. Electricalcontacts 4, 9, 2, 2A, 2B, and 2C transfer power and electrical signalsfrom the male connector 3 to spring pins 18 in the female connector 12.

Torsion member 37 and plain bearing 41 allow rotation of the male jointconnector subassembly portion 42 in relation to the base/drive support39. The rotation allowed by torsion member 37 reduces the torsionalstiffness of the connector about the axis of torsion member 37 so thattorsional shock loads transferred across the joint are minimized. Thereduced stiffness allowed by torsion member 37 also allows bettercontrol of torque passing through the joint. In the embodimentillustrated, joint torque is measured by means of strain gages 13A and13B mounted in male joint inner connector portion 42. It should be notedthat the strain gages or other load, torque, or position sensing devicescan be located in either or both of the male and female side connectors.

Detailed Description of the Second Embodiment

Another embodiment of the joint assembly 100 is shown in FIGS. 8 through16. As is shown in the drawings and particularly in FIG. 10, the jointassembly 100 has a male side connector 50 which slides into a femaleside connector 65. In this embodiment, a sliding motion along thealigned axes of the male side connector 50 and the female side connector65 is contemplated. A locking lever assembly 56 secures together the twoassociated limb segments attached to the respective male/female sideconnectors of the joint assembly.

When fully assembled as shown in FIG. 8 the joint assembly 100 forms acompact joint that provides robust mechanical attachment, multipleweather-sealed electrical connections, and integral torque sensing. Asis shown in particular in FIGS. 9-12, the mechanical attachment betweenfemale side connector 65 and male side connector 50 is achieved when aplurality of tabs 52 on a hub portion 74 b of the male side connectorslide into a plurality of slots or notches 62 in the socket/receiver ofthe female connector. Moreover, an indexing tab 51 slides into anindexing slot 63 in the female receiver 64 in order to correctly orientthe male side assembly in relation to the female side assembly.Naturally, the tabs, slots, or notches can be arranged in anyconfiguration and on either connector so as to facilitate positivetraction or engagement between the male and female connectors of thejoint for the purpose of transmitting torsional as well as axial loads.Electrical contact/communication can be achieved through flat contacts69, 70, 71, and 72 in male side connector 50 when such contacts engage aplurality of spring pins 68 in the female side connector 65.

The male side connector 50 is shown in an exploded view in FIG. 13. Ingeneral, the male connector 50 may include a cup or base portion 74 a,the load bearing hub or projection 74 b, a connection plug 75, a plugrecess 76, and electrical contacts 69, 70, 71, and 72. As with the firstembodiment, torque about the cylindrical axis (or axis of rotation) ofthe joint assembly can be measured by means of strain gauges 49A and 49Bmounted to the male connector 50 (as illustrated) or to the femaleconnector 65.

As is shown in the exploded views in FIGS. 14 and 15, the female sideconnector 65 may include a spring pin mounting circuit board 77,electrical spring pins 68 in spring pin blocks 78, a torsional member67, a backing sheet 79, a housing 80, a plain bearing 82, and a femalereceiver or socket 64. Power and ground contacts 69 and 70 (FIG. 13) caneach be contacted by multiple spring pins 68 to allow high electricalcurrents to flow across the joint assembly. In addition, knurling 83 canalso be formed on the body of the socket 49 of the female jointconnector 65 which increases the contact area with the toothed innerperiphery of the torsion member 67. Similarly, as best illustrated inFIG. 14, the housing 80 can be knurled or toothed so as to mesh with atoothed outer periphery of the torsion member 67. This helps improve themechanical bond and prevent or retard slipping between the torsionmember and the male and/or female joint connectors.

The locking lever assembly 56, shown in an exploded view in FIG. 16, canbe composed of a locking collar 54, a locking lever 57, a pin 86, a pullrod 88, and a nut 91. A head portion 87 of the pull rod 88 is pivotallysecured in a lobed end 85 of the lever 57 by the pin 86. Rotating thelever 57 causes a split 89 in the collar 54 to open or close, dependingon the direction of rotation. In this manner, when the lever assembly 56is placed in a locked state, it cinches the socket/receiver of thefemale connector about the hub portion of the male connector creating arigid joint connection. In addition, a locking lever guard 59 (FIGS.11-12) may also be provided and secured to the housing 80 by way offasteners 58A-58C. It should be appreciated that other locking leverassembly constructions can also be employed.

Operation of the Second Embodiment

In operation, the male side connector 50 and female side connector 65are attached to separate limb segments or modules (not shown for thisembodiment) that are to be joined together using the previouslydescribed joint assembly. In one embodiment, these can be a wrist and aforearm, for example. As is shown in FIG. 10, the joint is establishedby first sliding the tabs 52 of male connector 50 into slots 62 of thesocket/receiver 64 of female connector 65 (with the male and femalesides oriented so that indexing tab 51 engages indexing slot 63). Themale and female connectors are fully engaged when tabs 52 and 51 bottomin slots 62 and 63 of the receiver 64. When full engagement is achieved,power and ground contacts 69 and 70 are in intimate contact with aplurality of conductive spring pins 68, and communications contacts 71and 72 are each in intimate contact with a single spring pin 68.

To ensure that the male connector 50 and female connector 65 do notbecome disengaged during operation of the artificial, prosthetic, orrobotic limb, locking lever 57 (shown opened in FIG. 9) is pushed downinto the position shown in FIG. 8 to clamp female socket/receiver 64around hub portion 74 b (FIG. 13). The joint is thus established asshown in FIG. 8.

When the joint is fully established, tabs 52 and 51 transfer torque toslots/notches 62 and 63 in socket/receiver 64 in the female sideassembly 65. Electrical contacts 69, 70, 71, and 72 transfer electricalpower and electrical signals from the male connector 50 to spring pins68 in the female connector 65 thus establishing electrical communicationbetween the limb segments of the artificial limb.

Torsion member 67 and plain bearing 82 allow rotation of femalereceiver/socket 64 with respect to housing/base 80 about the cylindricalaxis of housing 80. The rotation allowed by torsion member 67 reducesthe torsional stiffness of the connector about the axis of spring 67 sothat torsional shock loads transferred across the joint are minimized.The reduced stiffness allowed by torsion member 67 also facilitatesbetter control of torque passing through the joint. Torque in the jointcan be measured by means of strain gages 49A and 49B mounted to the maleconnector 50. As discussed with respect to the first embodiment, otherknown means for measuring torque are also contemplated.

The modular limb joint assembly disclosed herein can be used to connectmultiple modules or segments of an associated modular limb in series. Itprovides a high strength mechanical connection capable of bearing hightorque and axial loads, as well as an integral electrical connection forpower and signals. It also includes integral torque sensing elements.Further, it provides an elastic element, compliance element, or torsionmember which enables some resiliency in the joint. It should be notedthat the torsion member may also serve as a series elastic elementwithin the joint assembly which is effectively in series between the“input” or driving end of the joint and the “output” or driven end ofthe joint. Such a series elastic element may act as low pass filtereffectively filtering out shock loads while providing enhanced forcecontrol and stability (particularly when coupled with load or torquesensors as described previously). A more detailed discussion of theadvantages of using a series elastic element can be found in U.S. Pat.No. 5,910,720 to Williamson, et al., the entire disclosure of which isincorporated herein by reference.

Typical artificial limbs, such as prosthetic arms or robot arms, aredesigned as a single integrated assembly which cannot be simply andquickly disassembled into component modules. Moreover, such arms are notdesigned with load and/or torque sensing elements which are integral tothe connector, since they do not even have a modular connector. Due tothe lack of easily connectible limb modules or segments, typicalman-made arms do not have a single assembly which combines themechanical and electrical interface with a load and/or torque sensor, aswell as a compliance element, as in the disclosed embodiments.

Disclosed has been a new and improved artificial limb, such as an arm,which comprises modular segments. With the system disclosed herein, thereliability and safety of the electrical connection can be improved. Atthe same time, an integral torque sensor can be provided along with acompliance or torsion element to allow the joint between two segments ofa limb to function better.

According to one embodiment of the present disclosure, there is provideda connecting device which electrically connects first and secondcomponents of an artificial limb. The connecting device comprises afirst component block including a blade and a second component blockincluding a socket in which the blade is selectively accommodated. Alocking clip can selectively secure the first component block to thesecond component block.

According to another embodiment of the present disclosure, a joint isprovided for an artificial limb. The joint comprises a first connectorincluding a blade and a first electrical contact surface and a secondconnector including a socket in which the blade is selectivelyaccommodated, the socket including a second electrical contact surface.A locking clip is provided for securing the first connector to thesecond connector. Electrical communication is achieved between the firstand second connectors when the first and second electrical contactsurfaces are in contact with each other.

The disclosure has been described with reference to several embodiments.Obviously, alterations and modifications will occur to others upon areading and understanding of this specification. It is intended toinclude all such modifications and alterations insofar as they comewithin the scope of the appended claims or the equivalents thereof.

1-9. (canceled)
 10. A joint assembly for releasably securing a first anda second segment of an associated modular limb, the joint assemblycomprising: a male connector including a base, a load bearing hubsecured to the base of the male connector, and at least one firstelectrical contact secured to the load bearing hub, the base of the maleconnector being adapted to be secured to one of the first and secondsegments of the associated modular limb; a female connector including abase, a load bearing socket secured to the base of the female connector,and at least one second electrical contact secured to the load bearingsocket, the socket being configured to selectively receive the hub ofthe male connector and the base of the female connector being adapted tobe secured to the other of the first and second segments of theassociated modular limb; wherein the at least one first electricalcontact is aligned with the at least one second electrical contact whenthe hub is received in the socket for establishing electricalcommunication between the first and second segments of the associatedmodular limb; and wherein the male connector and the female connectorcooperate to form a resilient yet releasable modular limb joint.
 11. Thejoint assembly of claim 10, further comprising a locking member forselectively securing the male connector to the female connector.
 12. Thejoint assembly of claim 10, wherein the hub includes one of a pluralityof tabs or notches and the socket includes the other of the plurality oftabs or notches, the plurality of tabs and the plurality of notchesbeing aligned when the hub is received into the socket for transmittinga torsional load across the first and second segments of the associatedmodular limb.
 13. The joint assembly of claim 10, wherein one of themale connector and the female connector includes a torsion member. 14.The joint assembly of claim 13, wherein the torsion member is ringshaped and disposed between the socket and the base of the femaleconnector, the socket being rotatably mounted to the base of the femaleconnector.
 15. The joint assembly of claim 10, wherein one of the maleconnector and the female connector includes a load sensor for measuringa torsional load across the joint.
 16. The joint assembly of claim 15,wherein the load sensor comprises one of a full, half, or quarter straingage bridge.
 17. The joint assembly of claim 16, wherein the strain gagebridge includes a first half and a second half, the first half of thebridge being disposed adjacent the hub at a first location spaced froman axis of rotation of the joint and the second half of the bridge beingdisposed adjacent the hub at a second location spaced from the axis ofrotation of the joint.
 18. The joint assembly of claim 10, furtherincluding a weathertight seal located between the male connector and thefemale connector. 19-26. (canceled)
 27. The joint assembly of claim 13wherein the torsion member is ring shaped and disposed between the maleconnector and the female connector.
 28. The joint assembly of claim 27wherein the torsion member allows relative rotation between the maleconnector and the female connector.
 29. The joint assembly of claim 13wherein the torsion member includes a pair of contact surfaces whichengage a respective contact surface of each of the male connector andthe female connector.
 30. A joint assembly for releasably securing afirst and a second segment of an associated modular limb, the jointassembly comprising: a male connector including a base, a load bearinghub secured to the base of the male connector, and at least one firstelectrical contact secured to the load bearing hub, the base of the maleconnector being adapted to be secured to one of the first and secondsegments of the associated modular limb; a female connector including abase, a load bearing socket secured to the base of the female connector,and at least one second electrical contact secured to the load bearingsocket, the socket being configured to selectively receive the hub ofthe male connector and the base of the female connector being adapted tobe secured to the other of the first and second segments of theassociated modular limb; wherein the at least one first electricalcontact is aligned with the at least one second electrical contact whenthe hub is received in the socket for establishing electricalcommunication between the first and second segments of the associatedmodular limb; a torsion member positioned between the male connector andthe female connector; and wherein the male connector and the femaleconnector cooperate to form a resilient yet releasable modular limbjoint.
 31. The joint assembly of claim 30, further comprising a lockingmember for selectively securing the male connector to the femaleconnector.
 32. The joint assembly of claim 30, wherein the hub includesone of a plurality of tabs or notches and the socket includes the otherof the plurality of tabs or notches, the plurality of tabs and theplurality of notches being aligned when the hub is received into thesocket for transmitting a torsional load across the first and secondsegments of the associated modular limb.
 33. The joint assembly of claim30, wherein the torsion member is ring shaped and disposed between thesocket and the base of the female connector, the socket being rotatablymounted to the base of the female connector.
 34. The joint assembly ofclaim 30, wherein one of the male connector and the female connectorincludes a load sensor for measuring a torsional load across the joint.35. The joint assembly of claim 34, wherein the load sensor comprisesone of a full, half, or quarter strain gage bridge.
 36. The jointassembly of claim 35, wherein the strain gage bridge includes a firsthalf and a second half, the first half of the bridge being disposedadjacent the hub at a first location spaced from an axis of rotation ofthe joint and the second half of the bridge being disposed adjacent thehub at a second location spaced from the axis of rotation of the joint.37. The joint assembly of claim 30, further including a weathertightseal located between the male connector and the female connector. 38.The joint assembly of claim 30 wherein the torsion member is ring shapedand disposed between the male connector and the female connector. 39.The joint assembly of claim 30 wherein the torsion member allowsrelative rotation between the male connector and the female connector.40. The joint assembly of claim 30 wherein the torsion member includes apair of contact surfaces which engage a respective contact surface ofeach of the male connector and the female connector.